1. Field of the Invention
This invention relates to an information recording device using a photosensitive medium for electrophotography to record desired information such as the output of a computer
2. Description of the Prior Art
As a recording device of the described type, there is known one which uses a so-called beam spot scanning device which scans and exposes a photosensitive medium for electrophotography by an information light such as a laser beam or the like.
Apparatus for scanning a laser beam spot have heretofore comprised a rotational polygon mirror for deflecting the laser beam and an f-.theta. lens or the like for condensing the deflected beam into a spot moving at a linear speed. In these prior art apparatus, however, various operating portions have been separate and independent and a predetermined light path interval has been required therebetween and therefore, precise adjustment during the assembly of the apparatus has been very much complicated and the assembled apparatus has been bulky.
Also, very high shape accuracy of the rotational polygon mirror and very high accuracy of the driving device have been required and this has resulted in a high cost of the apparatus. Further, such apparatus have been insufficient with respect to scanning speed.
There are also known apparatus which use an acoustic optical deflector instead of a rotational polygon mirror to make the apparatus compact. An example of such apparatus is disclosed in U.S. Pat. No. 3,514,534, but even in that example, various operating portions are still independent and therefore, cumbersome adjustment has been required during the assembly.
On the other hand, the thin film waveguide path light integration technique has recently been developed. This technique is introduced in T. Tamir, "Integrated Optics", Spinger Verlag Co., Inc. (1975), etc. and the contents thereof are concerned with the so-called optical integrated circuit. A novel beam spot scanning device by utilizing the above-mentioned technique has been proposed in U.S. patent application Ser. No. 228,744 filed Jan. 27, 1981, now U.S. Pat. No. 4,425,023, issued Jan. 10, 1984 by the same assignee of the subject application. This beam spot scanning device is to be called a scanning light forming optical integrated circuit (Integrated Optical Scanner: IOS), in which a light deflecting portion and a condensing thin film lens are formed on a thin film waveguide path and scanning of a beam spot is effected on or near the end surface of the thin film waveguide path. This IOS is very compact and capable of high-speed scanning.